We had a Honeywell 5220D installed by a HVAC company in April. Now my AC runs fine during the day and at night about 10PM the inside fan continues to run the thermostat is not yet at temp and the outside compressor fan does not run until the sun comes up. I have checked to see if it was in economy mode and it is not. The temp inside will warmup 6-8 degrees buy morning and the unit will come back on some time after we have gone to work. any ideas?
Thanks Gary
garyhenry@kw.com

Make sure the temper differ in cool mode are set 40-90 this is also a programable feature of this t-stat , by the way it also has offsets in the heat mode you might want to check this as well and make sure they are set check all wire connections for tightness and placement, also check to see if the t-stat is set to change from heat to cool auto mode or manual set to manual

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The condensor is not cooling fast enough. Try cleaning the condensor coil. Also check that the fan goes on. At night the outside temperature is cooler and does not need much work to cool down the condensor.

If the outdoor temps are cooler than inside, AC's are not made for this and will not work well if that is the situation, it floods liquid to the compressor which will overload. will it reset within 20 mins of going off? if so the board/stat are suspect, if not the compressors the villain and its tired and cant handle the other than design condition of 95 F outdoor/80F indoor.

Is this a new hvac system? A new furnace can work differently than your old one. Does it shut off after a minute or two or continue to run? If it continues to run then call that professional back and let him fix it. If it shuts down after a minute or two then it is a feature of the new thermostat to squeeze all of the cool it can from the a/c coil and ductwork.Some of them have settings that you can adjust for blower delay on and off, read the manual that came with the t-stat and see if it does.

If your coil is freezing at night, it sounds like your getting cold enough at night to have your saturation temperature drop below the design of what the AC is able to do. If it runs all day without an issue and freezes up at night, you need to add what is called an outdoor fan cycling switch. This will turn the condenser fan off when the saturation temperature drops so it will not freeze your coil at night. You need to have an HVAC technician install this. It is not a DIY projuect since it has adjustments that need to be right. Plus, it it's a heat pump, it needs to drop the switch off in the winter.

Pay attention to wires from control box itself at the ceiling assy. Sometimes they will use a different color from control box, to thermostat. For example: Green coming out of control box, is attached to a blue running to thermostat, so you would attach that blue, to "G" (fan) on thermostat. Match thermostat colors to what is at the control box originally, not what color they used to run it to thermostat from there. Most try to match them, but others don't. What model Ac unit, and what model of thermostat do you have?

Your thermostat Function 0170 must be set to "1" for Single Stage Heat/Cool. Function 0180 must be set for "0" for Heating Fan Control. Function 0240 must be set for "5" for the Heating Cycle Rate for your <90% Gas Furnace. If you have already done these steps or if, after doing these steps, you continue to experience a problem, you problem could be with your Gas Furnace. I'm including some links for information on your system and thermostat that include wiring diagrams. http://johnstonesupply9.com/TechDocs/Amana/Package%20Units%20Gas-Electric/PGD%20Pkg%20Gas%20Ele/PGD%20Tech%20Info.pdf

In your climate usually the defrost timer would be on 90. However if you are in an upper elevation and it gets colder then set it at 60. what model unit do you have? Did they change both indoor and outdoor units? I would have to know the model # to tell if the fan should run in defrost. In most cases I would say no.